THIAZOLO {8 5,4-c{9 ISOQUINOLINE AND THIAZOLO {8 4,5-c{9 IOSQUINOLINE AND DERIVATIVES AS ANTIFOGGANTS FOR PHOTOGRAPHIC LAYERS

ABSTRACT

Thiazolo (5,4-c) isoquinoline and thiazolo (4,5-c) isoquinoline and their derivatives are used in silver halide elements and emulsions in order to stabilize said elements and emulsions against fog.

United States Patent Dorothy J. Beavers;

Norman W. Kalenda, both 01 Rochester, NY.

Oct. 8, 1969 Dec. 28, 1971 Eastman Kodak Company Rochester, N.Y.

Inventors Appl. No. Filed Patented Assignee THIAZOLO [5,4-C11SOQUINOLINE AND 'll-IIAZOLO [4,5-C11OSQUINOLINE AND DERIVATIVES AS ANTIFOGGANTS FOR PHOTOGRAPHIC LAYERS 1 1 Claims, No Drawings US. 96/109, 96/66.5, 260/155, 260/302 C07d 35/34, C07d 91/42, G03c 1/34 Field of Search 96/ 109,

Int."

Primary ExaminerJohn T. Goolkasian Assistant Examiner-M. E. McCamish Attorneys-William H. J. Kline, Bernard D. Wiese and Allen P. Rosenberg ABSTRACT: Thiazolo [5,4-c]isoquinoline and thiazolo [4,5- c]isoquinoline and their derivatives are used in silver halide elements and emulsions in order to stabilize said elements and emulsions against fog.

TIIIAZOLO [SA-CIISOQUINOLINE AND THIAZOLO [4,5- CllOSQUINOLINE AND DERIVATIVES AS ANTIFOGGANTS FOR PHOTOGRAPHIC LAYERS BACKGROUND OF THE INVENTION 1. Field of the invention This invention relates to photography. In one aspect this invention relates to the stabilization of photographic silver halide elements and emulsions against spontaneous fog without adversely affecting the photographic sensitivity of said silver halide elements and emulsion.

2. Description of the Prior Art It is well-known that photographic silver halide on storage tends to lose sensitivity and to become spontaneously developable without exposure to light. The detectable amount of silver salt reduced during development of those areas where there is no exposure is commonly referred to as fog, and more specifically chemical fog where it is desirable to distinguish between it and the effects of accidental exposure to radiation.

Fog depends upon both the particular emulsion and the conditions of development. For a given emulsion fog increases with the degree of development. At constant development conditions fog generally increases with the temperature, time and relative humidity of storage conditions.

It is known that certain mercaptans, particularly those compounds having mercapto substitution on a heterocyclic ring, and certain organic disulfides have an antifoggant and stabilizing effect when incorporated in photographic silver halide emulsions. For example, U.S. Pat. No. 2,440,l l discloses organic disultides used in combination with sulfinic or seleninic acids or their salts, U.S. Pat. No. 2,819,965 describes the use of s-triazines having a carboxymethylmercapto substituent U.S. Pat. No. 2,935,404 describes bis-(s-triazolo[4,3-a] pyrimidine) disulfides, British Pat. No. 819,370 describes mercapto-1,2,4-triazines.

Quinolines have been used as emulsion addenda. P. Glafkides, Photographic Chemistry, (1958) Vol. 1, page 376 describes 2-aminothiazole-5,4',5,6-quinoline as a stabilizer for neutral and ammoniacal emulsions. lsoquinolines have been used as emulsion addenda, for example, U.S. Pat. No. 2,512,721 describes 3-methylisoquinoline as toners. The inventor is not aware of a disclosure showing the isoquinolines employed in this invention being used as photographic antifoggants.

Many of the prior art stabilizers are objectionable because they are not effective antifoggants unless used in combination with other materials, while other compounds have a desensitizing effect at concentrations wherein said compounds are most effective as antifoggants. It is therefore desirable to obtain compounds which are effective antifoggants for photographic silver halide layers without effecting a desensitization of said layers.

SUMMARY OF THE INVENTION In accordance with this invention, it has been found that significantly enhanced stability against chemical fog in photographic silver halides can be obtained while not seriously effecting a decrease in their photographic sensitivity. The enhanced stability and control over chemical fog is obtained through the use of compounds not known, heretofore, to have antifoggant properties.

It is the object, according to one aspect of this invention, to provide stabilized photographic silver halides.

It is another aspect of this invention to provide a method for stabilizing silver halides.

It is yet a further object to stabilize silver halide elements and emulsions without adversely affecting to any substantial degree, their photographic sensitivity.

It is a further object of this invention to provide photographic silver halides which are stabilized with a particular group of isoquinolines.

Other objects will become apparent from examination and consideration of the specification and claims.

DESCRIPTION OF THE PREFERRED EMBODIMENTS It has been found that certain isoquinolines act as strong antifoggants and stabilize photographic silver halides without causing a serious reduction in the photographic sensitivity. The isoquinolines which have been found useful can be a thiazolo[5,4-clisoquinoline, a thiazolo[4,5-c]isoquinoline, a 2-halo, hydroxy, thiol or aminothiazolo[5,4-clisoquinoline or a 2-halo, hydroxy, thiol or amino[4,5-clisoquinoline. The

compounds are represented by the general formulas:

and

wherein each R can be hydrogen, halide, hydroxy, thiol or amino.

It is to be understood that the isoquinoline portion of the compounds of this invention can be substituted with any radical, such as alkyl radicals, aryl radicals, and the like, as long as such substitutions do not destroy the antifoggant properties of the compound. Examples of the isoquinolines are:

2-aminothiazolo[5,4-c]isoquinoline 2-aminothiazolo[4,5-c]isoquinoline 2-chlorothiazolo[5,4-c]isoquinoline 2-chlorothiazolo[4,5-c]isoquinoline 2-hydroxythiazolo[5,4-clisoquinoline 2-hydroxythiazolo[4,5-c1isoquinoline thiazolo[5,4-c]isoquinoline-2-thiol thiazolo[4,5-clisoquinoline-Z-thiol The compounds of this invention are conveniently prepared by the method described in Hall and Taurins, Can. J. Chem., 44, 2465, 2473 (1966).

The concentration of the stabilizing compounds can vary considerably depending on various factors such as the effects desired, silver content of the photographic elements, the nature of the particular silver halide, the degree of ripening, the location of the stabilizer in relation to the silver halide, the particular stabilizer, etc. In general, a concentration in the range of about 0.00] grams to about 10 grams of stabilizer per mole of silver halide is useful. A preferred range is from about 0.03 grams to about 0.5 grams of stabilizer per mole of silver halide. In accordance with the invention, one may use the higher concentrations without inducing a reduction in sensitivity. The optimum concentration of stabilizer for a particular photographic system can be determined through techniques well known in the art.

The stabilizing addenda can be added in a variety of ways and at various stages in the preparation of the photographic system. The stabilizers can be incorporated directly into silver halide elements and emulsion, preferably before the final digestion operation in the case of emulsions and after the silver halide grains are substantially in their final size and shape. The addenda can be added to a layer adjacent to the silver halide layer. The solvents in which the stabilizers may be dissolved are restricted to those that are not harmful to the silver halide emulsion, and in accordance with the general practice organic solvents and diluents are preferred.

The light-sensitive silver halide emulsions comprising the antifoggants of this invention can contain addenda such as gelatin plasticizers, coating aids and hardeners such as the aldehyde-type hardeners, e.g., formaldehyde, mucochloric acid, glutaraldehyde bis(sodium bisulfite), maleic dialdehyde, and aziridines, dioxane derivatives, vinylsulfonylethers and oxypolysaccharides. Sensitizing dyes useful in sensitizing such emulsions are described, for example, in U.S. Pat. Nos. 2,526,632 of Brooker and White issued Oct. 24, 1950, and 2,503,776 of Sprague issued Apr. 11, 1950. Spectral sensitizers which can be used are the cyanines, merocyanines,

complex (trinuclear, cyanines, complex (trinuclear) merocyanines styryls and hemicyanines. Developing agents can also be incorporated into the emulsion if desired or can be contained in a separate underlayer.

Supports such as paper that are coated with alpha-olefin polymers, particularly polymers of alpha-olefins containing two or more carbon atoms, as for example, polyethylene, polypropylene, ethylene-butene copolymers and the like, can

The stabilizing addenda employed in the practice of this inalso be employed. vention can be used in various kinds of photographic emul- Photographic layers comprising the antifoggants can also sions. in addition to being useful in orthochromatic, panchron in Speed-increasing compounds such as quaternary ammatic and infrared emulsions, they are also useful in X-ray and monium compounds, polyethylene glycols or thioethers. other nonspectrally sensitized emulsions. They can be added eq y. useful effects can be Obtained y adding the r to the emulsions before, simultaneously or after any spectrally n i n Speed-increasing compounds to the photographic sensitizing dyes that may be used. They are particularly effecdeveloper Solutions instead in i i 1 the P tive in sulfur and gold-sensitized silver halide emulsions. Varigraphic y ous silver salts can be used as sensitive salts, including for ex- Silver halide emulsions containing the flmifoggants 0f the ample, silver bromide, silver iodide, silver chloride, silver instant invention can be sensitized using of the chlorobromide, silver bromoiodide, or silver chloroiodide and l f twhm'ilues emulsion f" p y 3 the like. The silver halides can be those which form latent mg with naturally active gelatin or Vanous 'v selem'um images predominantly on the surface of the silver halide grains tellul'lum Compounds and/0r gold compounds- The emulsions or those hi f knem images inside the Silver halide can also be sensitized with salts of noble metals of Group VIII erystalssueh as described in US. Pat. No. 2,592,250 of Davey of the Periodic Table which have an atomic weight greater and Knott issued Apr. 8, 1952. The subject addenda can be I used in emulsions intended for color photography, for examsllver hahde emulslolls f l the anufoggams of h pie, emulsions containing color forming couplers or emulsions l 2 can be used "l T Processes wh'ch m be developed by solutions Containing couphrs or other utilize the undeveloped silver halide in nonimage areas of the color-generating materials, emulsions of the mixed-packet- 2 F form a R w? y dlmlvmg, F Y type Such as described in Us paL 2,698,794 of silver halide and prec pitat ng it on a receiving layer in close Godowsky issued 4, 1955; in silver dye bleach Systems; proximity to the original silver halide emulsion layer. Such and emulsions of the mixed grain type Such as described in processes are described in U.S. Pat. Nos. 2,352,0l4 of Rott isus Pat. No. 2 592 243 of Carrol and Hanson issued Apr. 8 Sued June 1944; 2543,18 Land Sued 1952, l 30 and 3,020, l 55 of Yackel, Yutzy, Foster and Rasch issued Feb. in the preparation of the silver halide dispersions employed The h {also be F l" d'ffuslon transfer for preparing silver halide emulsions there can be employed as F P wlllch a dlffuslon transfer of an the dispersing agent, orubindersw as they are known in the an. i magewise distribution of developer, coupler or dye, from a for the silver halide in its preparation, gelatin or some other l layer to a second layer wh'le the two layers are colloidal material such as modified gelatin, colloidal albumin, m close proxlrfmy to one another, f h a cellulose derivative, a polyvinyl compound, acrylamide The 9 sixamples are mcluded for a er unpolymers, etc., although gelatin is preferred. Mixtures ofthese derstandmg of the binding agents can also be used. The binding agents for the EXAMPLES emulsion layer of the photographic element can also contain 40 dispersed polymerized vinyl compounds. Such compounds are Compounds employed in this invention, listed in the table disclosed, for example, in US. Pat. Nos. 3,142,568 of Nottorf below, are incorporated, at concentrations listed in the table, issued July 28, 1964; 3,193,386 of White issued July 6, 1965; into separate samples of a high-speed gelatino silver 3,062,674 of Houck, Smith and Yudelson, issued Nov. 30, bromoiodide photographic emulsion. Each of the emulsions 1965', and include the water-insoluble polymers of alkyl acryare coated on a cellulose acetate film support at a coverage of lates and methacrylates, acrylic acid, sulfoalkyl acrylates or 459 mg. ofsilver and 1,040 mg. ofgelatin per square foot. As a methacrylates and the like. comparison film strips absent the compounds of this invention The photographic emulsions stabilized according to this inare also prepared. A sample of each film coating is exposed on vention can be coated on a wide variety of supports. Typical an Eastman lB sensitometer, processed for five minutes in supports include those generally employed for photographic Kodak DK-50 Developer, fixed, washed and dried. Separate elements, as exemplified by cellulose nitrate film, cellulose samples of the film coating are incubated for two weeks at ester film, poly(vinyl acetal) film, polystyrene film, 120 F. and 50 percent relative humidity before exposure and poly(ethylene terephthalate) film and related films ofresinous development. The results of the sensitometric tests on the materials as well as glass, paper, metal, wood and the like. fresh and incubated samples are summarized in the table.

TABLE I 2 week incubation at 120 F., Fresh samples 50% relative humidity Stabilizing compounds Relative Relative (g./mo1e of Ag) speed Gamma Fog speed Gamma Fog 100 1. 42 17 46 1. 08 83 100 1. 52 17 83 1. 33 34 97 1. 48 18 94 1. 28 28 89 1. 4B 17 76 1. 32 39 68 1. 45 16 82 1. 3B .16 87 1. 52 19 57 1. 28 48 76 1. 45 18 69 1. 33 30 87 1. 33 17 100 l. 30 25 67 1. 2O .15 71 1. 30 .17

A=2-aminothiazolo[5,4-c lsoqulnoline. B =2 chlorothiazolol5,4-c C =2-hydroxythiazolo[5,4-ci]lsoquinolino. D thlazolo[5,4-c]isoquinol isoquinoline.

ne-Z-thiol.

The examples, as summarized in the table, show that the 4. A photographic silver halide emulsion comprising a stacompounds of this invention are highly useful as stabilizers bilizing compound selected from the general formulas; and fog inhibitors for photographic silver halides. It should be noted that fog is inhibited without any concurrent substantial "R Sfi-dt loss, if any, in the photographic sensitivity of the silver halide I N emulsion. In the case of the incubated samples the speed of the treated emulsions is always greater than the nontreated 6 samples. With respect to the fresh samples there was an insig- N nificant loss in speed, if any.

The invention, it is seen provides silver halide emulsions and 10 elements stabilized with the particular antifoggants said anwh i h R i h d h lid h d thin] or in tifoggants not causing any substantial deleterious effect upon id t bili i compound i present i a n ntration f speed or sensitivity. from about 0.001 to about l0.0 g. per mole of silver The invention has been described scribed in detail with parb i id ticular reference to preferred embodiments thereof, but it will A photographic emulsion as in Claim 4 wherein Said be understood that Variations and modifications can be bilizing compound is present in a concentration of from about fected within the spirit and scope of the invention. mg to about 5 per mole f Silver halide.

We claim:

1. A photographic element comprising a support, a silver halide layer and as a stabilizer a thiazolo[5,4-c]isoquinoline, a thiazolo[4,5-cisoquinoline, a 2-halo, hydroxy, thiol or aminothiazolo[5,4-c]isoquinoline or a 2-halo, hydroxy, thiol or aminothiazolo[4,5-c]isoquinoline.

2. A photographic element comprising a support, a silver halide layer and as a stabilizer a compound having the formula selected from the group consisting of 6. A photographic emulsion as in claim 4 wherein said stabilizer is 2-aminothiazolo[5,4-c]isoquinoline or 2- aminothiazolo[4,5-c]isoquinoline.

7. A photographic emulsion as in claim 4 wherein said stabilizer is 2-chlorothiazolo[5,4-c]isoquinoline or 2- chlorothiazolo[4,5-clisoquinoline.

5 8. A photographic emulsion as in claim 4 wherein said stabilizer is 2-hydroxythiazolo[5,4-c]isoquinoline or 2-hydroxythiazolo[4,5-c1isoquinoline. fi 9. A photographic emulsion as in claim 4 wherein said stal l N bilizer is thiazolo[5 ,4-clisoquinoline-Z-thiol or thiazolo[4,5-c]

30 isoquinoline-Z-thiol.

10. A photographic silver halide emulsion as in claim 4 wherein said silver halide emulsion is a high-speed gelatino silver bromoiodide emulsion.

wherein each R is hydrogen, halide hydroxy hiolwor aminol l. A method for stabilizing photographic silver halide A photographic element as in claim 2 wherein said Stabn againstfog which comprises contacting said silver halide with izer is present in a concentration of from about 0001 to astabilizmg compound havlngaformula according to claim 1.

about l0 g. per mole of silver halide.

PO-1O5O UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent N Dated ecember 28, Inventor-(s) o othy J. Beavers, et al.

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Title page, item [5M], line 2, "IOSQUINOLINE" Should read ISCQUINOLINE---.

Column 1, line 2, QUINOL Should read Column 1;, line 69, under heading "Stabilizing compounds (g./mole of g) HO. OO) should read ---E (O. 09)- Column 5, line 1h, "scribed" should be deleted.

In The Claims Column 5, line 2| that part of formula reading "17+, S-cisoquinoline should read Ll,5-g7isoquinoline--.

Column 5, line 28, that part of formula set forth as:

" S= -W R should be S'R Column 6, line 3,

"S B" should read R (V II.

Signed and sealed this 17th day of October 1972.

EDWARD M.FLET( 1HER, JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents 

2. A photographic element comprising a support, a silver halide layer and as a stabilizer a compound having the formula selected from the group consisting of
 3. A photographic element as in claim 2 wherein said stabilizer is present in a concentration of from about 0.001 g. to about 10 g. per mole of silver halide.
 4. A photographic silver halide emulsion comprising a stabilizing compound selected from the general formulas:
 5. A photographic emulsion as in claim 4 wherein said stabilizing compound is present in a concentration of from about 30 mg. to about 0.5 g. per mole of silver halide.
 6. A photographic emulsion as in claim 4 wherein said stabilizer is 2-aminothiazolo(5,4-c)isoquinoline or 2-aminothiazolo(4,5-c)isoquinoline.
 7. A photographic emulsion as in claim 4 wherein said stabilizer is 2-chlorothiazolo(5,4-c)isoquinoline or 2-chlorothiazolo(4,5-c)isoquinoline.
 8. A photographic emulsion as in claim 4 wherein said stabilizer is 2-hydroxythiazolo(5,4-c)isoquinoline or 2-hydroxythiazolo(4,5-c)isoquinoline.
 9. A photographic emulsion as in claim 4 wherein said stabilizer is thiazolo(5,4-c)isoquinoline-2-thiol or thiazolo( 4,5-c)isoquinoline-2-thiol.
 10. A photographic silver halide emulsion as in claim 4 wherein said silver halide emulsion is a high-speed gelatino silver bromoiodide emulsion.
 11. A method for stabilizing photographic silver halide against fog which comprises contacting said silver halide with a stabilizing compound having a formula according to claim
 1. 